In a computer-controlled sewing machine, for example of the type manufactured by Juki Corporation and sold as the Model AMS 220B, a generally rectangular clamping frame is commonly used to clamp a fabric material of a garment against a correspondingly shaped feed plate. The frame and feed plate are supported for movement in X-Y directions on top of the sewing machine table which is located under the head of the sewing machine. The clamping frame is moved in the X-Y directions with the feed plate and also in a Z direction between an upper released position and a lower clamping position by power operated manipulator controlled by a computer program. When the sewing machine is used to stitch an emblem or other patch onto fabric material forming part of a garment, it is desirable to stitch the patch to the material around the entire peripheral of the patch. This stitching operation is performed by placing the patch within the clamping frame, and then clamping the patch to the garment material by a clamping pad. The pad is positioned within the frame which defines a stitching path completely around the clamping pad.
In order to provide for continuous stitching of the patch to the garment around the entire peripheral of the patch, the clamping pad is supported by a U-shaped inversion arm having opposite projecting end shafts rotatably supported by bearings on the clamping pad and a supporting frame, for example, as disclosed in U.S. Pat. No. 5,146,859. The stitching operation is commenced within the U-shaped inversion arm which is rotated 180.degree. as the stitching operation progresses around the peripheral of the patch so that the stitching operation may return to the point where it commenced. The flip-flop rotation of the inversion arm through 180.degree. is produced by either actuation of a rotary solenoid or by moving a rack engaging a gear connected to the inversion arm.
In the rental uniform business, it is frequently desirable to attach multiple different size emblems or other patches to a garment. Usually, the different size patches are attached to the garment by using two separate computer-controlled sewing machines each equipped with a clamping frame and clamping pad for a particular size patch. The use of multiple machines adds significantly to the costs of attaching the patches. It is also known to use interchangeable clamping frames and corresponding interchangeable clamping pads on a single sewing machine. However, down time is required of the sewing machine for interchanging the clamping frames and pads, and this reduces the production rate of the sewing machine. It has also been proposed to use an adjustable clamping pad to accommodate different size patches, for example, as disclosed in above-mentioned U.S. Pat. No. 5,146,859. However, it is apparent that down time of the sewing machine is required to adjust the clamping pad for accommodating a different size patch, and additional time is required to pass each garment through the sewing machine for each patch.